ABB 1TNA900111R0150 Current Transformer KORC 4L 150/1

Let's break down the part number ABB 1TNA900111R0150 and its description KORC 4L 150/1.

This is a technical designation for a specific type of electrical component. Here’s a detailed explanation of what each part means.

Part Number Breakdown: 1TNA900111R0150

This is ABB's internal manufacturing code. While it looks complex, it can be decoded:

1TNA: This is a common prefix for ABB's measurement and protection devices, including current transformers.

900111: This is the unique article number or item code for this specific model.

R0150: This often refers to a specific variant or rating, in this case, likely confirming the primary current of 150A.

Description Breakdown: KORC 4L 150/1

This is the more human-readable technical description that tells you exactly what the product is.

KORC: This is the Product Series.

The KO series from ABB is a well-known range of resin-insulated, ring-type (window-type) current transformers.

The R typically stands for "Rated" or specifies a particular design feature of the series.

These are commonly used for indoor and outdoor applications in switchgear, panel boards, and substations.

4L: This indicates the Accuracy Class.

This is a crucial parameter. An accuracy class of 4L means the transformer is designed for metering purposes.

'4' indicates the accuracy is within ±4% at the rated current.

'L' indicates that the transformer has a low burden, meaning it can maintain its accuracy even when connected to devices (like energy meters) that have a very low power consumption.

150/1: This defines the Current Ratio.

150: The Primary Current (I_p). This is the current in the main conductor being measured. The transformer is designed to be used in circuits where the normal current is around 150 Amps.

1: The Secondary Current (I_s). This is the standardized output current. The transformer will output 1 Amp when 150 Amps is flowing through the primary conductor.

This 1A signal is what is safely fed to your measurement devices like ammeters, energy meters, or protection relays.

Summary of Key Specifications

Feature Specification Meaning

Manufacturer ABB A leading global technology company.

Product Series KORC Resin-insulated, ring-type current transformer.

Type Window Type (Ring Type) The main cable or busbar is passed through the hole in the center.

Primary Current (I_p) 150 A The current in the circuit being measured.

Secondary Current (I_s) 1 A The safe, scaled-down output current for instruments.

Ratio 150/1 For every 150A in, 1A comes out.

Accuracy Class 4L For metering, with ±4% accuracy and a low burden.

Insulation Resin Cast Robust and suitable for various industrial environments.

What is this used for?

This specific current transformer is primarily used for energy metering and measurement in low-voltage electrical installations. You would typically find it inside:

Electrical switchboards

Distribution panels

Motor Control Centers (MCCs)

It is used to safely monitor the current drawn by a feeder, a machine, or an entire section of a building's electrical system.

Important Note for Installation and Use:

Never Open-Circuit the Secondary! When a current transformer is in operation, the secondary terminals (S1 and S2) must never be open-circuited. They must always be connected to a meter or a shorting block. An open-circuited secondary can produce a dangerously high voltage, posing a severe safety risk and potentially damaging the transformer.